Cleansing the skin is a personal hygiene problem not always easily solved. Dry tissue products are the most commonly cleansing product used post-defecation or post-urine release. Dry tissue products are usually referred to as “toilet tissue” or “toilet paper”. Beside the use of dry tissue, it is becoming increasingly frequent to use wet wipes for the purpose of cleaning the anus, the perinea, and the peri-anal body area after defecation So called “Wet wipes” are a fibrous structure, generally of thick caliper, impregnated with a composition, usually water or oil-based.
Among those negatives associated with the failure of adequate cleansing are irritation, redness, desquamation, infections, unpleasant odor or other kind of personal discomfort or health related issues. People suffering from pathological conditions (such as hemorrhoids, fissures, cryptitis, etc.) are even more susceptible to those issues and discomfort. For them, as for any persons, cleansing must be efficient in terms of removal of fecal residues and gentle in terms of absence of irritation caused by the cleansing. Wet-Wipes bring a response to that basic need. For example, the Pampers Baby Fresh and regular baby wipes are marketed with a patent marking of U.S. Pat. No. 4,904,524.
The use of emulsions in lotion for wipes is widely spread. Most commonly use emulsion use an oil-in-water type of emulsion, having as key components an oily phase (in the form of an emollient), an emulsifier or surfactant component and an aqueous phase that comprises further additives such as antimicrobial agents.
Many patent documents intend to describe wipes with emulsion based lotions:
In EP808151B1, Blieszner et al, describe a composition for wipes and wipes using a composition that is useful for personal cleansing and for reducing the risk of perineal dermatitis. In WO-0241869, Hsu, Jay, C. et al. describe a paper product treated with oil-in-water emulsions. The paper product contains a lotion, an emollient, a fatty alcohol component in, an emulsifier component, and a skin conditioning component. All components presenting a defined percentage of the lotion and paper product.
U.S. Pat. Nos. 4,741,944 and 4,865,221 provide wet wipes having a liquid in the sheet and/or web. The liquid includes water, benzalkonium chloride, citric acid, disodium phosphate, trisodium ethylene diamine tetraacetic acid, polyethylene glycol-75 lanolin, cocoamphocarboxyglycinate, propylene glycol, methylparaben, propylparaben, butylparaben, polysorbate 20 and fragrance.
General background on emulsions and in particular in High Internal Phase Emulsions and their potential use in cosmetics can be found in:                U.S. Pat. No. 4,606,913 describing high internal phase emulsions having enhanced stability and their use in cosmetics.        U.S. Pat. No. 5,539,021 and U.S. Pat. No. 5,688,842 describing a method for making a high internal phase emulsion without phase inversion.        U.S. Pat. No. 5,362,418 describing an oil-in-water gel-like emulsion a comprising mono-alkyl phosphate salt.        U.S. Pat. No. 5,085,854 describing a translucent cosmetic emulsion comprising mono-alkyl phosphate salt.        In U.S. Pat. No. 4,776,976, Nakamura and Suzuki describe an oil in water emulsion comprising a basic amino acid salt of aliphatic phosphate group.        U.S. Pat. No. 5,976,604 and U.S. Pat. No. 4,379,755 describing an oil-in-water emulsion with high oil content, comprising a sucrose fatty ester.        WO 97/32559 describing a stable dispersion having a bi-liquid foam comprising oil droplets and suitable for cosmetic applications.        
Many of the above documents are directed at finding alternatives or improved ways to deliver better wipes performance.
In general, lotion compositions for wet wipes, and more specifically emulsions are manufactured by mixing an emollient compound into an excess of water and a surfactant or emulsifier. This process for making an emulsion however requires stringent process conditions, i.e., a high energy input to homogenize the oil and water phase and e.g., to generate a defined particle size distribution into the aqueous phase: generally a high shear mixing is needed together with the heating of the composition being prepared.
This high-energy input is costly for the manufacturer and requires specific equipment (i.e., significant investment level). Also, the high shear and stringent process conditions represent a significant stress on the ingredients of emulsions conventionally prepared (for example break-down of large molecular weight structures). Moreover the emulsions prepared by such conventional processes are by nature very diluted. Handling, storage and transportation represent significant inconvenience and cost.
Also, it there is a limit in particle size which can be achieved with traditional emulsion making processes (the particle size is the size of the oil droplets in the aqueous solution of the oil-in-water emulsion). Emulsions of low oil droplet size require generally most stringent preparation whereas it has been proven that low oil droplet size induces more desirable end properties for the emulsions.
It has been found that emulsions with small oil droplet size (=small particle size) deliver to the user an increased amount to of the emollient upon application.
There is a need for a wipe providing a smooth, long lasting comfortable feeling to the user. There is also a need for an emulsion composition applied to a wipe that is relatively easy and cost efficient to prepare and preserve. There is additionally a need for a way to prepare such emulsions that would be cost efficient and would enable storage and transportation of the emulsion in a concentrated form.
There is a further need for a process to prepare such wipes comprising an emulsion that would preferably only require low energy input, and in particular low shear and little or no heat input. There is also a need for a process to prepare such wipes comprising an emulsion process that would provide a low shear stress to the ingredients. There is additionally a need for a way to prepare an emulsion exhibiting oil droplets that are of very small dimension and are stable and/or meta-stable.
There is a need for the preparation of an universal emulsion premix or concentrate to which the various additives corresponding to the desired properties could be added subsequently. There is finally a need for a way to prepare such an emulsion combining all or most of the above benefits to a so far unachieved level.